Compensation watch-balance.



No. 798,993. PATENTED SEPT. 5, 1 905. G. GULMAN.

COMPENSATION WATCH BALANCE.

APPLIUATION FILED NOV. 25, 1904.

Ca/r/ a/m an I Q I Q. m IAUIGIW. D. I.

5 rod 6, which is preferably of steel.

. UNITED STATES PATENT OFFICE.

CARL CULMAN, OF ST. LOUIS, MlSSOUltl.

COMPENSATION WATCH-BALANCE.

Specification of Letters Patent.

Patented Sept. 5, 1905.

Application filed November 25, 1904:. Serial No. 284,262.

and useful Improvements in Temperature Adjustments for Balance-VVheels;and I do de clare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it ap- IO pertains to make and use the same.

My invention relates to improvements in contin uous or self-adjustingtemperature compensations for the balance wheels of chronometers,watches, and other timepieces; and

5 it consists in certain novel features of construction, combination,and arrangement of parts hereinafter fully described and claimed.

The object of my invention is to provide a simple and efficient deviceof this character by means of which the air resistance offered by thebalance-wheel will be automatically varied to compensate for thevariation in the strength of the balance-spring and the size of thebalance-wheel, which variation occurs as 5 the said parts expand andcontract under changes of temperature.

The above and other objects, which will appear as the nature of myinvention is more fully understood, are accomplished by the con- 3struction illustrated in the accompanying drawings, in which Figure 1 isa plan view of a watch-balance with my improvements applied thereto.Fig. 2 is a vertical sectional view taken on the line 2 2 in Fig. l, andFig. 3 is a similar view taken on the line 3- 3 in Fig. 1.

Referring to the drawings by numeral, 1 denotes a watch balance wheel ofordinary construction consisting of two segmental bi- 4 metallicrim-sections 2, supported from the ends of an arm 3, which is attachedto the balance-staff 4c. The rim-sections 2 of the wheel are disposed inthe usual manner, so that they form a perfect circle when in theirnormal positions, and have the usual weights or screws 5 connected tothem, as shown. Extending through each of said rim-sections 2, adjacentto their ends and in substantially parallel relation with the main armor bar 3, is a bar or Each of said rods 6 passes freely through andslides in an opening 7, formed in the fixed end of one of therim-sections, and has one of its ends screw-threaded, as at 8, to permitit to be adj ustably secured in a similarly screw-threaded opening 9,formed in the free end of the said rim-section. Upon the opposite end ofsaid rod outside of said rim-section is a head or weight 10, which maybe of any suitable form.

It will be seen that when the parts are in the position seen in Fig. 1of the drawings and are adjusted for a moderate temperature therim-sections 2 form a perfect circle, so that the air offersa certainresistance to the movement of the wheel, which resistance will of coursevary as the shape or size of the wheel varies when the rim-sectionsexpand or contract under changes of temperature. Vhen the temperature ofthe parts of the device lowers and the balance-spring contracts andbecomes stronger, the rim-sections will contract and change the shape ofthe wheel, and thereby lessen the amount of its resistance; but owing tothe manner in which said heads or weights 10 are mounted this loss ofresistance caused by the change in the shape of the wheel will becompensated for by the outward movement of said heads or weights.Similarly when the temperature rises and the balance-spring expands andbecomes weaker the rim-sections will expand to increase the airresistance; but this increase will be compensated for by the inwardmovement of the said heads or weights 10. It is thus seen that the wheelwill be self-adjusting or automatic in its compensation for the extremesor changes of temperature. By adjusting the length of the rods or bars6, which carry the heads or weights 10, the wheel may be set orregulated for any normal temperature, as will be readily understood.

From the foregoing description, taken in connection with theaccompanying drawings, the construction and operation of the inventionwill be readily understood without requiring a more extendedexplanation.

Various changes in the form, proportion, and the minor details ofconstruction may be resorted to without departing from the principle orsacrificing any of the advantages of this invention.

Having thus described my invention, what 1 claim as new, and desire tosecure by Letters Patent, is-

l. A balance-wheel havinga rim-section secured at one end and having theopposite end free, and an approximately radially disposed compensatingarm having one end secured to p near the secured end of the latter,being free to move with relation thereto and having a weight at its freeend.

2. A balance-whcel having a rim-section secured at one end and havingthe opposite end free, and an approximately radially disposedcompensating arm having one end adjustably secured to the free end ofthe rim-section for longitudinal adjustment on said arm, the latterextending across the rim-section, near the secured end thereof, beingfree to move with relation to the secured end of the rim-section andhaving a weight at its free end. V

3. A balance for ClllOIlOl'llGtQXS, watches and other timepieces,comprising bimetallic, segmental arms or rim-sections, rods having theirinner ends secured in the free ends of said arms and their outer endsextending transversely with respect to the fixed ends of said arms, andheads or weights upon the outer ends of my hand in presence of twosubscribing witnesses.

CARL OULMAN. \Vitnesses:

IRA G. MoUnY, THOMAS JARVIS.

